On the marriott website put in "Lake Buena Vista" rather than Orlando. All the ones listed will be very close. I've stayed in most of them and all are good. HTH
I just got back from a short stay there. It's huge! It's on 536 across from the Nickelodeon Kids Suites hotel. Not a bad drive to Disney property at all.
We just got back from the Courtyard by Marriott at Vista Center on Palm Parkway which is about 2 minutes from the back entrace to WDW(by Downtown Disney/Hotel Plaza Blvd). It was beautiful and close to everything. We will definately go there again.